Janus is the ancient Roman god whose name gave January its name and whose two faces symbolize looking backward and forward.
Roman writers associated Janus with beginnings, transitions, doorways and passages. His two faces were conventionally understood as facing in opposite directions, making him an especially fitting symbol for the change from an old year to a new one.
January is named from the Latin Ianuarius. In the Roman calendar reforms associated with the early Roman state and later the Julian calendar, January became the first month of the year in the civil calendar used by Rome.
Janus is not the same figure as Saturn, the god celebrated during Saturnalia, or Mars, the god of war. Roman New Year's customs could include offerings to Janus and exchanges of good wishes, practices that helped connect the month with fresh starts and public transitions.